Nitration apparatus



' May 15', 1923.

H. V. WALKER NITRATION APPARATUS Filed May 20, 1920 2 Sheet-Sheet 1 May 15, 1923. 1,454,870

' H. v. WALKER NI TRATION APPARATUS Filed May 130,. 1920 2 Sheets-Sheet 2 Patented May is, 1923.

HENRY V. WALKER, OF NEWARK, NEW JERSEY.

NITRATIOH APPARATUS.

Application fil'ed May 20, 1920. Serial No. 382,810.

To all whom it may concern:

- Be it known that I, HENRY V. WALKER, a citizen of the United States, residin in Newark, county of Essex, State of i ew Jersey, have invented a certain Improvement in Nitration Apparatus, of which the following is a specification. I

The present invention has relation to an improvement-in processes for nitration of cellulose and the like, whereby the same is rendered continuousyas well as to certain new and useful improvements in the apparatus for carrying on the process in question in an eificient, safe and economical maimer.

In the manufacture of nitro-cellulose or guncott'on, the rawjcottonis first subjected to the action of sulphuric and nitric acids in suitable proportion to produce the necessary nitrating reaction. The excess acid is then removed so far as possible by mechanical action, and this process is finally completed by a series of boiling and washing operations to render. the product thoroughly es'stahle; V

It has been common, hitherto, to carry on the nitratingprocess in the basket of a centrifugal separator, and, after the mixture has stood for a suilicient time to complete the reaction, the separator is set-running, so

' asto accomplish the mechanical extraction, of the excess free acid. The boiling and Washing processes follow this centrifugal extraction process.

By thus using. the centrifugal machine as a dipping chamber, a good deal of time is lost, because the Inachine'is prevented from carrying out its proper natural function as an extractor during the time occupied by the the chemical reaction. The same waste of time is involved where the dipping is done in a separate chamber which is ClI'SChaIQOCl into the waiting centrifugal machine after completion of each reaction. V

The present invention involves a process wherein a succession of charges of mixed cotton (or equivalent substance) is conveyed in a continuous series by intermittent movements, suitably timed; from a charging point to the point of extraction, and wherein the extracting process on the one hand and the charging process on the other hand are accomplished simultaneously at opposite ends of the moving series, during the time intervals between the successive forward movements of the charges. It is a novel characteristic 0f myimproved process that, durin the forward movement of the material, it is given agentle agitation.

By this plan it isclear that a suflicient time can be given to carr out the nitration of each charge while it is moving forward through the series of allotted positions;-while, on the other hand, the extracting machine is kept busy all the time, be-

' mg emptied after each extraction and placed ',in readiness for the next charge in the series.

Another important advantage presented by this process is found in the fact that it admits ofautomatic control of the time of nitration. In prior systems the time of nitration is subject to the control of the 0pcrator, but in the present system this is not the case as the first charge cannot leave the. dipping series until a number (preferably four) subsequent charges have been introduced into-the series. Sufficient time for nitration is thus insured for every charge.

The apparatus forming a part 'Of this invention has the advanta 'e of great simplicity in construction and ticularly in regard to the acid piping, and the disposition of fumes.

A preferred form of the apparatus is illustrated in the accompanying drawings, wherein Figure l'is a diagrammatic side elevation, partly in section, of the complete apparatus, Figure 2 is an end View of the nitratingcylinder viewed from the left in Figure 1, Figure 3 is a sectio'nal view of the apparatus on the line in Figure lfiand Figoperation parure 4 is a detail. view of the. discharge end of the nitrating cylinder. 'lhe nitrating cylinder 10 is furnished with an internal partition ll extending. in a wide spiral from end to end of the cyl-. indcr. The outer edge of this spiral of heli all partition is closely united to the interior of the cylinder, preferably by Welding; and it thus divides the cylinder into four chambers 01' compartments. Central openings 12 are formed in the successive spirals, serving both to facilitate construction and to make it possible to carry off from i all the compartments the fumes which are normally disengaged during nitration.

At. the charging end of the cylinder, a

door 13 is furnished, through which :the operator may introduce the cotton and mix 1t, by means of an iron fork, with the heated.

bands 16 and 17 are may be run in through the piping 14. The discharging end of the cylinder 10 is provided with a discharge chute 15.

Suitable means are employed whereby the cylinder and its internal partition may be revolved upon their common axis; and" for this purpose, in the form shown, friction provided which rest upon friction wheels l8, 19 near each end.

The wheels 19 are fixed to a common driving shaft 20, by means of which they are made to drive the cylinder 10. Any motive .means (automatic or otherwise) may be used for driving the shaft 20; as, for instance, an electric motor 21, acting through the belt 22, and clutch 23. This clutch, is operated by the handle 24:, so that the revolution of the cylinder may be controlled by the operator.

At the discharge end of the cylinder 10 is placed the centrifugal acid extractor 25 which may be of any well known form, the details of which need no illustration. It'is preferred to employ the type of extractor in acids which which aremovable basket 26 is used, which can be removed and replaced by suitable mechanism, as, for instance, the pneumatic lift 2.7.

Just beyond the extractor 25 is placed the washing tank 28 for removing the excess free acid from the cotton which leaves the extractor. This is preferably provided with a raised perforated bottom 29, from under which the water may be drawn off through the drain 30.

I A. fume-hood 31 extends over the extractor 25 and over the front end of the tank 28; and fume pipes 32, 33 extend out from under this hood, through which the fumes are drawn oil in a well known manner. The motor-for driving the .-entrifugal acid extractoris indicated at 34.

he improved process is carricdmut in .this apparatus follows- The heated acids are introduced by the operator into the first nitrating compartment, together with the proper quantity of cotton. The chargethus formed fills this charging compartment up to a level somewhat under the lower edge of the door 13; through which the operator can manipulate the charge by means of a suitable tool. The mixture being accomplished, the cylinder is rotated through a single revolution and is then stopped.

This results in transferring the entire charge to the second compartment, leaving the first or charging compartment empty,

time, the friction of the rotating walls of the helix serve to promote amild agitation in the mixture.

The operations thus far described are repeated indefinitely, with the result that each charge in succession is finally brought into the last compartment, in which, as shown at 35 in Figure 4, the helix is so shaped as to 26 of the centrifugal exa new charge by return of the basket to its place. At the same time the first compartment is being char ed, as already described.

It will be seen that, by this arrangement, there is a series of successive charges moving step by step toward the extractor which is thus kept always in operation, except during the necessary removal and return of the inner basket. As each charge has to move through the whole series of positions before being delivered to the extractor, ample time for nitration is provided. This time can be regulated by thenumber of positions and the time it takes to charge and to extract. In practice, it has been found that good results are achieved by the use of four compartments and four positions of rest, but, of course, the invention. is not limited to any given number of positions.

b'o tar as the invention relates to the apparatus, other means than shown might be employed for transferring the charges from one position to the next, and. in general the claims are not limited to the details shown and described, save asezvprcssly stated in the claim.

\Vhat is claimed is- A nitrating apparatus comprising a rotatable nitrating container having a mixing door at one end and an interior peripheral helical partition providing a succession of pockets at the bottom for limited bodies of mixture, and means for feeding acids into the compartment near the charging end of the container.

In testimony whereof I have hereto set my hand on this 18th day of May'lElQO.

HENRY v. WALKER.

falls by gravity into the and ready for'a new charge. At the same 7 

